From patchwork Wed Apr  8 08:53:17 2020
Content-Type: text/plain; charset="utf-8"
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
X-Patchwork-Submitter: Heiko Stuebner <heiko@sntech.de>
X-Patchwork-Id: 202302
Return-Path: <SRS0=8MPa=5Y=vger.kernel.org=devicetree-owner@kernel.org>
X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on
 aws-us-west-2-korg-lkml-1.web.codeaurora.org
X-Spam-Level: 
X-Spam-Status: No,
 score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, 
 INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE,
 SPF_PASS, 
 USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0
Received: from mail.kernel.org (mail.kernel.org [198.145.29.99])
 by smtp.lore.kernel.org (Postfix) with ESMTP id 12E80C2D0EA
 for <linux-devicetree@archiver.kernel.org>;
 Wed,  8 Apr 2020 08:53:41 +0000 (UTC)
Received: from vger.kernel.org (vger.kernel.org [209.132.180.67])
 by mail.kernel.org (Postfix) with ESMTP id 848DC2074F
 for <linux-devicetree@archiver.kernel.org>;
 Wed,  8 Apr 2020 08:53:40 +0000 (UTC)
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
 id S1726345AbgDHIxk (ORCPT
 <rfc822;linux-devicetree@archiver.kernel.org>);
 Wed, 8 Apr 2020 04:53:40 -0400
Received: from gloria.sntech.de ([185.11.138.130]:42890 "EHLO gloria.sntech.de"
 rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
 id S1725763AbgDHIxj (ORCPT <rfc822;devicetree@vger.kernel.org>);
 Wed, 8 Apr 2020 04:53:39 -0400
Received: from ip5f5aa64a.dynamic.kabel-deutschland.de ([95.90.166.74]
 helo=phil.lan) by gloria.sntech.de with esmtpsa
 (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.89)
 (envelope-from <heiko@sntech.de>)
 id 1jM6Sg-0004Gq-UB; Wed, 08 Apr 2020 10:53:31 +0200
From: Heiko Stuebner <heiko@sntech.de>
To: dri-devel@lists.freedesktop.org
Cc: thierry.reding@gmail.com, robh+dt@kernel.org,
 devicetree@vger.kernel.org, mark.rutland@arm.com,
 christoph.muellner@theobroma-systems.com, heiko@sntech.de,
 sam@ravnborg.org, Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
Subject: [PATCH v3 2/2] drm/panel: add panel driver for Leadtek LTK050H3146W
Date: Wed,  8 Apr 2020 10:53:17 +0200
Message-Id: <20200408085317.2624599-2-heiko@sntech.de>
X-Mailer: git-send-email 2.24.1
In-Reply-To: <20200408085317.2624599-1-heiko@sntech.de>
References: <20200408085317.2624599-1-heiko@sntech.de>
MIME-Version: 1.0
Sender: devicetree-owner@vger.kernel.org
Precedence: bulk
List-ID: <devicetree.vger.kernel.org>
X-Mailing-List: devicetree@vger.kernel.org

From: Heiko Stuebner <heiko.stuebner@theobroma-systems.com>

The LTK050H3146W is 5.0" 720x1280 DSI display. There are two variants
with essentially the same name, LTK050H3146W and LTK050H3146W-A2.

They differ in their init sequence and mode details.

changes in v2:
- add display variants
changes in v3:
- fixed indentation and artifacts found by Sam

Signed-off-by: Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
---
 drivers/gpu/drm/panel/Kconfig                 |  11 +
 drivers/gpu/drm/panel/Makefile                |   1 +
 .../drm/panel/panel-leadtek-ltk050h3146w.c    | 691 ++++++++++++++++++
 3 files changed, 703 insertions(+)
 create mode 100644 drivers/gpu/drm/panel/panel-leadtek-ltk050h3146w.c

diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
index a1723c1b5fbf..d56258b9fcaf 100644
--- a/drivers/gpu/drm/panel/Kconfig
+++ b/drivers/gpu/drm/panel/Kconfig
@@ -137,6 +137,17 @@ config DRM_PANEL_KINGDISPLAY_KD097D04
 	  24 bit RGB per pixel. It provides a MIPI DSI interface to
 	  the host and has a built-in LED backlight.
 
+config DRM_PANEL_LEADTEK_LTK050H3146W
+	tristate "Leadtek LTK050H3146W panel"
+	depends on OF
+	depends on DRM_MIPI_DSI
+	depends on BACKLIGHT_CLASS_DEVICE
+	help
+	  Say Y here if you want to enable support for Leadtek LTK050H3146W
+	  TFT-LCD modules. The panel has a 720x1280 resolution and uses
+	  24 bit RGB per pixel. It provides a MIPI DSI interface to
+	  the host and has a built-in LED backlight.
+
 config DRM_PANEL_LEADTEK_LTK500HD1829
 	tristate "Leadtek LTK500HD1829 panel"
 	depends on OF
diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
index 96a883cd6630..2335a1e32ae0 100644
--- a/drivers/gpu/drm/panel/Makefile
+++ b/drivers/gpu/drm/panel/Makefile
@@ -12,6 +12,7 @@ obj-$(CONFIG_DRM_PANEL_ILITEK_ILI9881C) += panel-ilitek-ili9881c.o
 obj-$(CONFIG_DRM_PANEL_INNOLUX_P079ZCA) += panel-innolux-p079zca.o
 obj-$(CONFIG_DRM_PANEL_JDI_LT070ME05000) += panel-jdi-lt070me05000.o
 obj-$(CONFIG_DRM_PANEL_KINGDISPLAY_KD097D04) += panel-kingdisplay-kd097d04.o
+obj-$(CONFIG_DRM_PANEL_LEADTEK_LTK050H3146W) += panel-leadtek-ltk050h3146w.o
 obj-$(CONFIG_DRM_PANEL_LEADTEK_LTK500HD1829) += panel-leadtek-ltk500hd1829.o
 obj-$(CONFIG_DRM_PANEL_LG_LB035Q02) += panel-lg-lb035q02.o
 obj-$(CONFIG_DRM_PANEL_LG_LG4573) += panel-lg-lg4573.o
diff --git a/drivers/gpu/drm/panel/panel-leadtek-ltk050h3146w.c b/drivers/gpu/drm/panel/panel-leadtek-ltk050h3146w.c
new file mode 100644
index 000000000000..5a7a31c8513e
--- /dev/null
+++ b/drivers/gpu/drm/panel/panel-leadtek-ltk050h3146w.c
@@ -0,0 +1,691 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020 Theobroma Systems Design und Consulting GmbH
+ */
+
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/media-bus-format.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/regulator/consumer.h>
+
+#include <video/display_timing.h>
+#include <video/mipi_display.h>
+
+#include <drm/drm_mipi_dsi.h>
+#include <drm/drm_modes.h>
+#include <drm/drm_panel.h>
+#include <drm/drm_print.h>
+
+struct ltk050h3146w_cmd {
+	char cmd;
+	char data;
+};
+
+struct ltk050h3146w;
+struct ltk050h3146w_desc {
+	const struct drm_display_mode *mode;
+	int (*init)(struct ltk050h3146w *ctx);
+};
+
+struct ltk050h3146w {
+	struct device *dev;
+	struct drm_panel panel;
+	struct gpio_desc *reset_gpio;
+	struct regulator *vci;
+	struct regulator *iovcc;
+	const struct ltk050h3146w_desc *panel_desc;
+	bool prepared;
+};
+
+static const struct ltk050h3146w_cmd page1_cmds[] = {
+	{ 0x22, 0x0A }, /* BGR SS GS */
+	{ 0x31, 0x00 }, /* column inversion */
+	{ 0x53, 0xA2 }, /* VCOM1 */
+	{ 0x55, 0xA2 }, /* VCOM2 */
+	{ 0x50, 0x81 }, /* VREG1OUT=5V */
+	{ 0x51, 0x85 }, /* VREG2OUT=-5V */
+	{ 0x62, 0x0D }, /* EQT Time setting */
+/*
+ * The vendor init selected page 1 here _again_
+ * Is this supposed to be page 2?
+ */
+	{ 0xA0, 0x00 },
+	{ 0xA1, 0x1A },
+	{ 0xA2, 0x28 },
+	{ 0xA3, 0x13 },
+	{ 0xA4, 0x16 },
+	{ 0xA5, 0x29 },
+	{ 0xA6, 0x1D },
+	{ 0xA7, 0x1E },
+	{ 0xA8, 0x84 },
+	{ 0xA9, 0x1C },
+	{ 0xAA, 0x28 },
+	{ 0xAB, 0x75 },
+	{ 0xAC, 0x1A },
+	{ 0xAD, 0x19 },
+	{ 0xAE, 0x4D },
+	{ 0xAF, 0x22 },
+	{ 0xB0, 0x28 },
+	{ 0xB1, 0x54 },
+	{ 0xB2, 0x66 },
+	{ 0xB3, 0x39 },
+	{ 0xC0, 0x00 },
+	{ 0xC1, 0x1A },
+	{ 0xC2, 0x28 },
+	{ 0xC3, 0x13 },
+	{ 0xC4, 0x16 },
+	{ 0xC5, 0x29 },
+	{ 0xC6, 0x1D },
+	{ 0xC7, 0x1E },
+	{ 0xC8, 0x84 },
+	{ 0xC9, 0x1C },
+	{ 0xCA, 0x28 },
+	{ 0xCB, 0x75 },
+	{ 0xCC, 0x1A },
+	{ 0xCD, 0x19 },
+	{ 0xCE, 0x4D },
+	{ 0xCF, 0x22 },
+	{ 0xD0, 0x28 },
+	{ 0xD1, 0x54 },
+	{ 0xD2, 0x66 },
+	{ 0xD3, 0x39 },
+};
+
+static const struct ltk050h3146w_cmd page3_cmds[] = {
+	{ 0x01, 0x00 },
+	{ 0x02, 0x00 },
+	{ 0x03, 0x73 },
+	{ 0x04, 0x00 },
+	{ 0x05, 0x00 },
+	{ 0x06, 0x0a },
+	{ 0x07, 0x00 },
+	{ 0x08, 0x00 },
+	{ 0x09, 0x01 },
+	{ 0x0a, 0x00 },
+	{ 0x0b, 0x00 },
+	{ 0x0c, 0x01 },
+	{ 0x0d, 0x00 },
+	{ 0x0e, 0x00 },
+	{ 0x0f, 0x1d },
+	{ 0x10, 0x1d },
+	{ 0x11, 0x00 },
+	{ 0x12, 0x00 },
+	{ 0x13, 0x00 },
+	{ 0x14, 0x00 },
+	{ 0x15, 0x00 },
+	{ 0x16, 0x00 },
+	{ 0x17, 0x00 },
+	{ 0x18, 0x00 },
+	{ 0x19, 0x00 },
+	{ 0x1a, 0x00 },
+	{ 0x1b, 0x00 },
+	{ 0x1c, 0x00 },
+	{ 0x1d, 0x00 },
+	{ 0x1e, 0x40 },
+	{ 0x1f, 0x80 },
+	{ 0x20, 0x06 },
+	{ 0x21, 0x02 },
+	{ 0x22, 0x00 },
+	{ 0x23, 0x00 },
+	{ 0x24, 0x00 },
+	{ 0x25, 0x00 },
+	{ 0x26, 0x00 },
+	{ 0x27, 0x00 },
+	{ 0x28, 0x33 },
+	{ 0x29, 0x03 },
+	{ 0x2a, 0x00 },
+	{ 0x2b, 0x00 },
+	{ 0x2c, 0x00 },
+	{ 0x2d, 0x00 },
+	{ 0x2e, 0x00 },
+	{ 0x2f, 0x00 },
+	{ 0x30, 0x00 },
+	{ 0x31, 0x00 },
+	{ 0x32, 0x00 },
+	{ 0x33, 0x00 },
+	{ 0x34, 0x04 },
+	{ 0x35, 0x00 },
+	{ 0x36, 0x00 },
+	{ 0x37, 0x00 },
+	{ 0x38, 0x3C },
+	{ 0x39, 0x35 },
+	{ 0x3A, 0x01 },
+	{ 0x3B, 0x40 },
+	{ 0x3C, 0x00 },
+	{ 0x3D, 0x01 },
+	{ 0x3E, 0x00 },
+	{ 0x3F, 0x00 },
+	{ 0x40, 0x00 },
+	{ 0x41, 0x88 },
+	{ 0x42, 0x00 },
+	{ 0x43, 0x00 },
+	{ 0x44, 0x1F },
+	{ 0x50, 0x01 },
+	{ 0x51, 0x23 },
+	{ 0x52, 0x45 },
+	{ 0x53, 0x67 },
+	{ 0x54, 0x89 },
+	{ 0x55, 0xab },
+	{ 0x56, 0x01 },
+	{ 0x57, 0x23 },
+	{ 0x58, 0x45 },
+	{ 0x59, 0x67 },
+	{ 0x5a, 0x89 },
+	{ 0x5b, 0xab },
+	{ 0x5c, 0xcd },
+	{ 0x5d, 0xef },
+	{ 0x5e, 0x11 },
+	{ 0x5f, 0x01 },
+	{ 0x60, 0x00 },
+	{ 0x61, 0x15 },
+	{ 0x62, 0x14 },
+	{ 0x63, 0x0E },
+	{ 0x64, 0x0F },
+	{ 0x65, 0x0C },
+	{ 0x66, 0x0D },
+	{ 0x67, 0x06 },
+	{ 0x68, 0x02 },
+	{ 0x69, 0x07 },
+	{ 0x6a, 0x02 },
+	{ 0x6b, 0x02 },
+	{ 0x6c, 0x02 },
+	{ 0x6d, 0x02 },
+	{ 0x6e, 0x02 },
+	{ 0x6f, 0x02 },
+	{ 0x70, 0x02 },
+	{ 0x71, 0x02 },
+	{ 0x72, 0x02 },
+	{ 0x73, 0x02 },
+	{ 0x74, 0x02 },
+	{ 0x75, 0x01 },
+	{ 0x76, 0x00 },
+	{ 0x77, 0x14 },
+	{ 0x78, 0x15 },
+	{ 0x79, 0x0E },
+	{ 0x7a, 0x0F },
+	{ 0x7b, 0x0C },
+	{ 0x7c, 0x0D },
+	{ 0x7d, 0x06 },
+	{ 0x7e, 0x02 },
+	{ 0x7f, 0x07 },
+	{ 0x80, 0x02 },
+	{ 0x81, 0x02 },
+	{ 0x82, 0x02 },
+	{ 0x83, 0x02 },
+	{ 0x84, 0x02 },
+	{ 0x85, 0x02 },
+	{ 0x86, 0x02 },
+	{ 0x87, 0x02 },
+	{ 0x88, 0x02 },
+	{ 0x89, 0x02 },
+	{ 0x8A, 0x02 },
+};
+
+static const struct ltk050h3146w_cmd page4_cmds[] = {
+	{ 0x70, 0x00 },
+	{ 0x71, 0x00 },
+	{ 0x82, 0x0F }, /* VGH_MOD clamp level=15v */
+	{ 0x84, 0x0F }, /* VGH clamp level 15V */
+	{ 0x85, 0x0D }, /* VGL clamp level (-10V) */
+	{ 0x32, 0xAC },
+	{ 0x8C, 0x80 },
+	{ 0x3C, 0xF5 },
+	{ 0xB5, 0x07 }, /* GAMMA OP */
+	{ 0x31, 0x45 }, /* SOURCE OP */
+	{ 0x3A, 0x24 }, /* PS_EN OFF */
+	{ 0x88, 0x33 }, /* LVD */
+};
+
+static inline
+struct ltk050h3146w *panel_to_ltk050h3146w(struct drm_panel *panel)
+{
+	return container_of(panel, struct ltk050h3146w, panel);
+}
+
+#define dsi_dcs_write_seq(dsi, cmd, seq...) do {			\
+		static const u8 d[] = { seq };				\
+		int ret;						\
+		ret = mipi_dsi_dcs_write(dsi, cmd, d, ARRAY_SIZE(d));	\
+		if (ret < 0)						\
+			return ret;					\
+	} while (0)
+
+static int ltk050h3146w_init_sequence(struct ltk050h3146w *ctx)
+{
+	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
+	int ret;
+
+	/*
+	 * Init sequence was supplied by the panel vendor without much
+	 * documentation.
+	 */
+	dsi_dcs_write_seq(dsi, 0xdf, 0x93, 0x65, 0xf8);
+	dsi_dcs_write_seq(dsi, 0xb0, 0x01, 0x03, 0x02, 0x00, 0x64, 0x06,
+			  0x01);
+	dsi_dcs_write_seq(dsi, 0xb2, 0x00, 0xb5);
+	dsi_dcs_write_seq(dsi, 0xb3, 0x00, 0xb5);
+	dsi_dcs_write_seq(dsi, 0xb7, 0x00, 0xbf, 0x00, 0x00, 0xbf, 0x00);
+
+	dsi_dcs_write_seq(dsi, 0xb9, 0x00, 0xc4, 0x23, 0x07);
+	dsi_dcs_write_seq(dsi, 0xbb, 0x02, 0x01, 0x24, 0x00, 0x28, 0x0f,
+			  0x28, 0x04, 0xcc, 0xcc, 0xcc);
+	dsi_dcs_write_seq(dsi, 0xbc, 0x0f, 0x04);
+	dsi_dcs_write_seq(dsi, 0xbe, 0x1e, 0xf2);
+	dsi_dcs_write_seq(dsi, 0xc0, 0x26, 0x03);
+	dsi_dcs_write_seq(dsi, 0xc1, 0x00, 0x12);
+	dsi_dcs_write_seq(dsi, 0xc3, 0x04, 0x02, 0x02, 0x76, 0x01, 0x80,
+			  0x80);
+	dsi_dcs_write_seq(dsi, 0xc4, 0x24, 0x80, 0xb4, 0x81, 0x12, 0x0f,
+			  0x16, 0x00, 0x00);
+	dsi_dcs_write_seq(dsi, 0xc8, 0x7f, 0x72, 0x67, 0x5d, 0x5d, 0x50,
+			  0x56, 0x41, 0x59, 0x57, 0x55, 0x70, 0x5b, 0x5f,
+			  0x4f, 0x47, 0x38, 0x23, 0x08, 0x7f, 0x72, 0x67,
+			  0x5d, 0x5d, 0x50, 0x56, 0x41, 0x59, 0x57, 0x55,
+			  0x70, 0x5b, 0x5f, 0x4f, 0x47, 0x38, 0x23, 0x08);
+	dsi_dcs_write_seq(dsi, 0xd0, 0x1e, 0x1f, 0x57, 0x58, 0x48, 0x4a,
+			  0x44, 0x46, 0x40, 0x1f, 0x42, 0x1f, 0x1f, 0x1f,
+			  0x1f, 0x1f, 0x1f, 0x1f, 0x1f, 0x1f, 0x1f, 0x1f);
+	dsi_dcs_write_seq(dsi, 0xd1, 0x1e, 0x1f, 0x57, 0x58, 0x49, 0x4b,
+			  0x45, 0x47, 0x41, 0x1f, 0x43, 0x1f, 0x1f, 0x1f,
+			  0x1f, 0x1f, 0x1f, 0x1f, 0x1f, 0x1f, 0x1f, 0x1f);
+	dsi_dcs_write_seq(dsi, 0xd2, 0x1f, 0x1e, 0x17, 0x18, 0x07, 0x05,
+			  0x0b, 0x09, 0x03, 0x1f, 0x01, 0x1f, 0x1f, 0x1f,
+			  0x1f, 0x1f, 0x1f, 0x1f, 0x1f, 0x1f, 0x1f, 0x1f);
+	dsi_dcs_write_seq(dsi, 0xd3, 0x1f, 0x1e, 0x17, 0x18, 0x06, 0x04,
+			  0x0a, 0x08, 0x02, 0x1f, 0x00, 0x1f, 0x1f, 0x1f,
+			  0x1f, 0x1f, 0x1f, 0x1f, 0x1f, 0x1f, 0x1f, 0x1f);
+	dsi_dcs_write_seq(dsi, 0xd4, 0x00, 0x00, 0x00, 0x0c, 0x06, 0x20,
+			  0x01, 0x02, 0x00, 0x60, 0x15, 0xb0, 0x30, 0x03,
+			  0x04, 0x00, 0x60, 0x72, 0x0a, 0x00, 0x60, 0x08);
+	dsi_dcs_write_seq(dsi, 0xd5, 0x00, 0x06, 0x06, 0x00, 0x30, 0x00,
+			  0x00, 0x00, 0x00, 0x00, 0xbc, 0x50, 0x00, 0x05,
+			  0x21, 0x00, 0x60);
+	dsi_dcs_write_seq(dsi, 0xdd, 0x2c, 0xa3, 0x00);
+	dsi_dcs_write_seq(dsi, 0xde, 0x02);
+	dsi_dcs_write_seq(dsi, 0xb2, 0x32, 0x1c);
+	dsi_dcs_write_seq(dsi, 0xb7, 0x3b, 0x70, 0x00, 0x04);
+	dsi_dcs_write_seq(dsi, 0xc1, 0x11);
+	dsi_dcs_write_seq(dsi, 0xbb, 0x21, 0x22, 0x23, 0x24, 0x36, 0x37);
+	dsi_dcs_write_seq(dsi, 0xc2, 0x20, 0x38, 0x1e, 0x84);
+	dsi_dcs_write_seq(dsi, 0xde, 0x00);
+
+	ret = mipi_dsi_dcs_set_tear_on(dsi, 1);
+	if (ret < 0) {
+		DRM_DEV_ERROR(ctx->dev, "failed to set tear on: %d\n",
+			      ret);
+		return ret;
+	}
+
+	msleep(60);
+
+	return 0;
+}
+
+static const struct drm_display_mode ltk050h3146w_mode = {
+	.hdisplay	= 720,
+	.hsync_start	= 720 + 42,
+	.hsync_end	= 720 + 42 + 8,
+	.htotal		= 720 + 42 + 8 + 42,
+	.vdisplay	= 1280,
+	.vsync_start	= 1280 + 12,
+	.vsync_end	= 1280 + 12 + 4,
+	.vtotal		= 1280 + 12 + 4 + 18,
+	.clock		= 64018,
+	.width_mm	= 62,
+	.height_mm	= 110,
+};
+
+static const struct ltk050h3146w_desc ltk050h3146w_data = {
+	.mode = &ltk050h3146w_mode,
+	.init = ltk050h3146w_init_sequence,
+};
+
+static int ltk050h3146w_a2_select_page(struct ltk050h3146w *ctx, int page)
+{
+	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
+	u8 d[3] = { 0x98, 0x81, page };
+
+	return mipi_dsi_dcs_write(dsi, 0xff, d, ARRAY_SIZE(d));
+}
+
+static int ltk050h3146w_a2_write_page(struct ltk050h3146w *ctx, int page,
+				      const struct ltk050h3146w_cmd *cmds,
+				      int num)
+{
+	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
+	int i, ret;
+
+	ret = ltk050h3146w_a2_select_page(ctx, page);
+	if (ret < 0) {
+		DRM_DEV_ERROR(ctx->dev, "failed to select page %d: %d\n",
+			      page, ret);
+		return ret;
+	}
+
+	for (i = 0; i < num; i++) {
+		ret = mipi_dsi_generic_write(dsi, &cmds[i],
+					     sizeof(struct ltk050h3146w_cmd));
+		if (ret < 0) {
+			DRM_DEV_ERROR(ctx->dev,
+				      "failed to write page %d init cmds: %d\n",
+				       page, ret);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static int ltk050h3146w_a2_init_sequence(struct ltk050h3146w *ctx)
+{
+	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
+	int ret;
+
+	/*
+	 * Init sequence was supplied by the panel vendor without much
+	 * documentation.
+	 */
+	ret = ltk050h3146w_a2_write_page(ctx, 3, page3_cmds,
+					 ARRAY_SIZE(page3_cmds));
+	if (ret < 0)
+		return ret;
+
+	ret = ltk050h3146w_a2_write_page(ctx, 4, page4_cmds,
+					 ARRAY_SIZE(page4_cmds));
+	if (ret < 0)
+		return ret;
+
+	ret = ltk050h3146w_a2_write_page(ctx, 1, page1_cmds,
+					 ARRAY_SIZE(page1_cmds));
+	if (ret < 0)
+		return ret;
+
+	ret = ltk050h3146w_a2_select_page(ctx, 0);
+	if (ret < 0) {
+		DRM_DEV_ERROR(ctx->dev, "failed to select page 0: %d\n", ret);
+		return ret;
+	}
+
+	/* vendor code called this without param, where there should be one */
+	ret = mipi_dsi_dcs_set_tear_on(dsi, 0);
+	if (ret < 0) {
+		DRM_DEV_ERROR(ctx->dev, "failed to set tear on: %d\n",
+			      ret);
+		return ret;
+	}
+
+	msleep(60);
+
+	return 0;
+}
+
+static const struct drm_display_mode ltk050h3146w_a2_mode = {
+	.hdisplay	= 720,
+	.hsync_start	= 720 + 42,
+	.hsync_end	= 720 + 42 + 10,
+	.htotal		= 720 + 42 + 10 + 60,
+	.vdisplay	= 1280,
+	.vsync_start	= 1280 + 18,
+	.vsync_end	= 1280 + 18 + 4,
+	.vtotal		= 1280 + 18 + 4 + 12,
+	.clock		= 65595,
+	.width_mm	= 62,
+	.height_mm	= 110,
+};
+
+static const struct ltk050h3146w_desc ltk050h3146w_a2_data = {
+	.mode = &ltk050h3146w_a2_mode,
+	.init = ltk050h3146w_a2_init_sequence,
+};
+
+static int ltk050h3146w_unprepare(struct drm_panel *panel)
+{
+	struct ltk050h3146w *ctx = panel_to_ltk050h3146w(panel);
+	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
+	int ret;
+
+	if (!ctx->prepared)
+		return 0;
+
+	ret = mipi_dsi_dcs_set_display_off(dsi);
+	if (ret < 0) {
+		DRM_DEV_ERROR(ctx->dev, "failed to set display off: %d\n",
+			      ret);
+		return ret;
+	}
+
+	mipi_dsi_dcs_enter_sleep_mode(dsi);
+	if (ret < 0) {
+		DRM_DEV_ERROR(ctx->dev, "failed to enter sleep mode: %d\n",
+			      ret);
+		return ret;
+	}
+
+	regulator_disable(ctx->iovcc);
+	regulator_disable(ctx->vci);
+
+	ctx->prepared = false;
+
+	return 0;
+}
+
+static int ltk050h3146w_prepare(struct drm_panel *panel)
+{
+	struct ltk050h3146w *ctx = panel_to_ltk050h3146w(panel);
+	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
+	int ret;
+
+	if (ctx->prepared)
+		return 0;
+
+	DRM_DEV_DEBUG_DRIVER(ctx->dev, "Resetting the panel\n");
+	ret = regulator_enable(ctx->vci);
+	if (ret < 0) {
+		DRM_DEV_ERROR(ctx->dev,
+			      "Failed to enable vci supply: %d\n", ret);
+		return ret;
+	}
+	ret = regulator_enable(ctx->iovcc);
+	if (ret < 0) {
+		DRM_DEV_ERROR(ctx->dev,
+			      "Failed to enable iovcc supply: %d\n", ret);
+		goto disable_vci;
+	}
+
+	gpiod_set_value_cansleep(ctx->reset_gpio, 1);
+	usleep_range(5000, 6000);
+	gpiod_set_value_cansleep(ctx->reset_gpio, 0);
+	msleep(20);
+
+	ret = ctx->panel_desc->init(ctx);
+	if (ret < 0) {
+		DRM_DEV_ERROR(ctx->dev, "Panel init sequence failed: %d\n",
+			      ret);
+		goto disable_iovcc;
+	}
+
+	ret = mipi_dsi_dcs_exit_sleep_mode(dsi);
+	if (ret < 0) {
+		DRM_DEV_ERROR(ctx->dev, "Failed to exit sleep mode: %d\n", ret);
+		goto disable_iovcc;
+	}
+
+	/* T9: 120ms */
+	msleep(120);
+
+	ret = mipi_dsi_dcs_set_display_on(dsi);
+	if (ret < 0) {
+		DRM_DEV_ERROR(ctx->dev, "Failed to set display on: %d\n", ret);
+		goto disable_iovcc;
+	}
+
+	msleep(50);
+
+	ctx->prepared = true;
+
+	return 0;
+
+disable_iovcc:
+	regulator_disable(ctx->iovcc);
+disable_vci:
+	regulator_disable(ctx->vci);
+	return ret;
+}
+
+static int ltk050h3146w_get_modes(struct drm_panel *panel,
+				  struct drm_connector *connector)
+{
+	struct ltk050h3146w *ctx = panel_to_ltk050h3146w(panel);
+	struct drm_display_mode *mode;
+
+	mode = drm_mode_duplicate(connector->dev, ctx->panel_desc->mode);
+	if (!mode)
+		return -ENOMEM;
+
+	drm_mode_set_name(mode);
+
+	mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
+	connector->display_info.width_mm = mode->width_mm;
+	connector->display_info.height_mm = mode->height_mm;
+	drm_mode_probed_add(connector, mode);
+
+	return 1;
+}
+
+static const struct drm_panel_funcs ltk050h3146w_funcs = {
+	.unprepare	= ltk050h3146w_unprepare,
+	.prepare	= ltk050h3146w_prepare,
+	.get_modes	= ltk050h3146w_get_modes,
+};
+
+static int ltk050h3146w_probe(struct mipi_dsi_device *dsi)
+{
+	struct device *dev = &dsi->dev;
+	struct ltk050h3146w *ctx;
+	int ret;
+
+	ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	ctx->panel_desc = of_device_get_match_data(dev);
+	if (!ctx->panel_desc)
+		return -EINVAL;
+
+	ctx->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
+	if (IS_ERR(ctx->reset_gpio)) {
+		DRM_DEV_ERROR(dev, "cannot get reset gpio\n");
+		return PTR_ERR(ctx->reset_gpio);
+	}
+
+	ctx->vci = devm_regulator_get(dev, "vci");
+	if (IS_ERR(ctx->vci)) {
+		ret = PTR_ERR(ctx->vci);
+		if (ret != -EPROBE_DEFER)
+			DRM_DEV_ERROR(dev,
+				      "Failed to request vci regulator: %d\n",
+				      ret);
+		return ret;
+	}
+
+	ctx->iovcc = devm_regulator_get(dev, "iovcc");
+	if (IS_ERR(ctx->iovcc)) {
+		ret = PTR_ERR(ctx->iovcc);
+		if (ret != -EPROBE_DEFER)
+			DRM_DEV_ERROR(dev,
+				      "Failed to request iovcc regulator: %d\n",
+				      ret);
+		return ret;
+	}
+
+	mipi_dsi_set_drvdata(dsi, ctx);
+
+	ctx->dev = dev;
+
+	dsi->lanes = 4;
+	dsi->format = MIPI_DSI_FMT_RGB888;
+	dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST |
+			  MIPI_DSI_MODE_LPM | MIPI_DSI_MODE_EOT_PACKET;
+
+	drm_panel_init(&ctx->panel, &dsi->dev, &ltk050h3146w_funcs,
+		       DRM_MODE_CONNECTOR_DSI);
+
+	ret = drm_panel_of_backlight(&ctx->panel);
+	if (ret)
+		return ret;
+
+	drm_panel_add(&ctx->panel);
+
+	ret = mipi_dsi_attach(dsi);
+	if (ret < 0) {
+		DRM_DEV_ERROR(dev, "mipi_dsi_attach failed: %d\n", ret);
+		drm_panel_remove(&ctx->panel);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void ltk050h3146w_shutdown(struct mipi_dsi_device *dsi)
+{
+	struct ltk050h3146w *ctx = mipi_dsi_get_drvdata(dsi);
+	int ret;
+
+	ret = drm_panel_unprepare(&ctx->panel);
+	if (ret < 0)
+		DRM_DEV_ERROR(&dsi->dev, "Failed to unprepare panel: %d\n",
+			      ret);
+
+	ret = drm_panel_disable(&ctx->panel);
+	if (ret < 0)
+		DRM_DEV_ERROR(&dsi->dev, "Failed to disable panel: %d\n",
+			      ret);
+}
+
+static int ltk050h3146w_remove(struct mipi_dsi_device *dsi)
+{
+	struct ltk050h3146w *ctx = mipi_dsi_get_drvdata(dsi);
+	int ret;
+
+	ltk050h3146w_shutdown(dsi);
+
+	ret = mipi_dsi_detach(dsi);
+	if (ret < 0)
+		DRM_DEV_ERROR(&dsi->dev, "Failed to detach from DSI host: %d\n",
+			      ret);
+
+	drm_panel_remove(&ctx->panel);
+
+	return 0;
+}
+
+static const struct of_device_id ltk050h3146w_of_match[] = {
+	{
+		.compatible = "leadtek,ltk050h3146w",
+		.data = &ltk050h3146w_data,
+	},
+	{
+		.compatible = "leadtek,ltk050h3146w-a2",
+		.data = &ltk050h3146w_a2_data,
+	},
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, ltk050h3146w_of_match);
+
+static struct mipi_dsi_driver ltk050h3146w_driver = {
+	.driver = {
+		.name = "panel-leadtek-ltk050h3146w",
+		.of_match_table = ltk050h3146w_of_match,
+	},
+	.probe	= ltk050h3146w_probe,
+	.remove = ltk050h3146w_remove,
+	.shutdown = ltk050h3146w_shutdown,
+};
+module_mipi_dsi_driver(ltk050h3146w_driver);
+
+MODULE_AUTHOR("Heiko Stuebner <heiko.stuebner@theobroma-systems.com>");
+MODULE_DESCRIPTION("DRM driver for Leadtek LTK050H3146W MIPI DSI panel");
+MODULE_LICENSE("GPL v2");